Expanding screw anchor



May 15,1923.

, '.l. BLACKBURN EXPANDI NG SCREW ANCHOR Filed Feb. 9, 1922 Il ,455, B 63 Patented ay l5, 1923.

oraria.

JASPER BLACKBURN, OF ST. LOUIS, lllIISSOUR.

EXPANDING SCREW ANCHOR..

Application filed. February To all whom t may concern.'

Be it known that I, Jnsrnn BLaoiieUiaN, a citizen of the United States, and resident ot the city of St. Louis and State oi Missouri, have invented certain new and useful Improvements in Expanding Screw Air chore, ot which the Afollowing' is a specification containing a 'ull, clear, and exact description, reference being had to the accompanying drawings, Aforming a part hereof. i

My invention relates to improvements in expanding' screw anchors, and has 'tor its primary object a screw anchor carrying ex panding plates, which anchor is adapted to he inserted in the ground by a twisting or boring movement, and when the proper depth has been reached, the plates are expanded into the solid ground so as to pre-` vent the withdrawal of the anchor.

A further object is to construct an expanding screw anchor in which the expanding plates are pushed into the ground surrounding the bore by the same wrench which is used to drive the anchor in the ground.

Tn the drawings,

,Figa 1 .is aside elevation ot my device with portions thereof broken away, and poi1` tions in section.

i the wrench shown in dotted lines.

ln the construction of my device T employ a boring member having a iiat plate which has formed integral with its lower portion a boss 6, this boss tapering to a point as indicated by the numeral 7. A portion of the plate 5 is cut away as indicated by the numeral 8. The boss 6 is provided with a helix 9, -which loosens the ground and conveys it upward to the opening 8, thus allowing` the plate 5 to sink downward into the ground. The boss 6 is provided with a screw-threaded opening 10, which opens into a bore 11. This bore is cored in and eliminates the use 01": a bottoming tap when forming the screw threaded bore 10. Extending through the wall of the boss 6 and communicating with the opening 11 is an opening 12, through which a tool can be inserted for mutilating the threads 13 on the rod 111. The upper end of the rod is screw threaded, as indicated at 9, 1922. Serial No. 535,213.

15. Pivotally secured to the plate 5 by means of rivets or the like 16, are expanding plates 17. These plates are so shaped as to cover substantially the entire plate 5, with the exception ot the opening 8. The outer edges ot the plates 17 are beveled as 18, to permit them being readily forced into the solid earth which. surrounds the bore. The upper 'face of the plate 5 is provided with an integral rib 19 which acts as a stop for the plates 17 when closed. The plate 5 is also provided with a rib 20. This rib is a part oif the helix, and is tor the pur` pose of directing the earth carried upward to the plates 17. Formed integral with the plates 17 and projecting upwardly therefrom, are bosses 21. These bosses are provided with a central opening 22, and an undercut portion 23, which are for the purpose ot permitting the insertion or' the ex` panding member 2a. This expanding member consists ot a cylindrical portion with which are integrally formed cam arms 25, the upper portion having a rectangular portion 26. The expanding member is provided with a central bore 27, through which the rod 1d passes, and the expanding member is held in position on the rod by means of a collar 28. The rectangular portion 26 is of substantially the same size as the upper portion of the bosses 21, which when the plates are collapsed form substantially a rectangular projection, and over these two rectangular portions is placed a wrench 29. This wrench is turned by means of a handle 30 which4 is adjustably mounted there on. llllien screwing the anchor into the ground, the eye is placed in position on the rod 111, and the cylindrical projection 32 formed on the underside oi the eye enters the wrench 29, and steadies the upper portion thereof.

The operation oi my device is as follows:

After the device together with the wrench has been assembled, as shown in Fig. 1, the plate 5 is turned, and by means of the helix 9 is gradually drawn into the ground. When a sutiicient depth has been reached, the eye 31 is screwed upward so that the wrench can be raised sutliciently that when it is turned it will only operate the expanding member 2-1 which is loosely mounted on the rod 111. 1When the wrench has been raised suiiiciently high, it is turned again by means o't the handle. At this period the cam arms 25 come in contact with the recesses 23 and force the plates apart as shown in Fig. 3. This forces the plates outward into the solid ground around the bore formed in driving` the anchor down, and prevents it froml pulling up bei'ore the loose ground oi the bore has had a chance to settle. The eye 31 is then removed entirely from the rod 14, and the wrench Q9 and handle 30 removed from the rod, after which the eye is again replaced for the purpose of securing the guy wire or rope thereto.

By the use of my device no twisting of the anchor rod 14C is necessary, and the same can be securely fastened within the plate 5, and with the elimination of any twisting` of the rod 14, there will consequently be no danger of fracturing` the rod either wholly or partially, and thus weaken it.

Having fully described my invention, what I claim is:

1. An expanding screw anchor comprising` a boring member in the form of a disc, a pointed projection formed integral with the underside of said disc, a helix encircling said pointed projection and integral therewith and with said disc, an opening formed in said disc tadjacent the upper portion ot' said helix, expanding plates pivotally secured to the upper surface of said disc, a rod secured in said disc and projection, an expanding member loosely located on said rod, means for preventing lateral movement oi' said expanding member, under cut projections integrally formed with the expanding plates, said under cut projections surrounding the lower portion of the exp'anding member, a rectangular portion formed integral with the expanding member and above the under cut projections, and a wrench `for insertingsaid anchor into the ground and for rotating the expanding member for forcing the expanding blades outward when the anchor is sunk into the ground.

2. An expanding screw anchor comprising a boring member in the 'form of a disc, al pointed projection formed integral with the underside ot' said disc, a helix encircling said' pointed projection and integral therewith and with said disc, an opening formed in said disc adjacent the upper portion of said helix, expanding` plates pivotally secured to the upper surface oi said disc, a rod secured in said disc and projection, an expanding member loosely located on said rod, means for preventing lateral movement of said expanding` member, under cut projections integrally formed with the expanding plates, said under cut projections surrounding the lower portion of the expanding member, a rectangular portion formed integral with the expanding member and above the under cut projections, a wrench for inserting said anchor into the ground and for rotating the expanding member for forcing the expanding` blades outward when the anchor is sunk into the ground, and an eye having a cylindrical projection screw seated on the upper portion of the rod, said cylindrical projection adapted to steady the upper end ci' the wrench.

3. An expanding screw Vanchor comprising a boring member in the form of a disc, a pointed projection formed integral with the underside of said disc, a helix encircling said projection and integral therewith and with said disc, an opening formed in said disc adjacent the upper portion of said helix, expanding plates pivotally secured to the upper surface of said disc, a rod secured in said disc and projection, an expanding member loosely mounted on said rod, means for preventing lateral movement of said expanding member, undercut projections integrally lformed with the expanding plates, said under cut projections surrounding the lower portion ol the expanding member, a rectangular portion formed integral with the expanding member and above the under cut projections, awrench for inserting said anchor into the ground, said wrench adapted `to be raised and engage the rectangular portion ot' thel expanding member for forcing the expanding plates outward when tlie'ancho'r is sunk into the ground, an eye li'avil'ig a cylindrical projection screw seated on the' upper portion olf the rod, said cylindrical portion adapted to` steady the upper end of the wrench.

ln testimony whereof, I have signed my name to this specification.

JASPER BLACKBURN. 

